Photography 101 - Lesson 3
Back by popular demand! Well folks, it’s been a while since I added to our Photography 101 series. I apologize for the absence! Frankly, I wasn’t sure if people were even reading what I wrote. But, thanks to a flurry of requests, I’ll get to it again.
As I’ve said in previous entries, I’m not the best photographer in the world. There are people on TravelBlog.org who blow my mind. But, what I do have is the time and care to pass on the knowledge I’ve learned. If you disagree with anything I post, please let me know and we’ll see if we can revise it. If you have any questions please comment and I’ll see what I can do to answer them.
The Final Component Shutter Speed
As we’ve noted in previous sessions of Photography 101
, photography is all about capturing light on some sort of medium, be it film or a digital sensor. The way you capture this light is A) set the amount of let you’ll allow to hit the medium by choosing the size of the hole light can enter through and then B) set the amount of time you let light through that opening. As we noted in Photography 101 Lesson 2
, the size of the hole that lets light in is called Aperture. Once the Aperture is set, the final component to getting a good picture is setting the amount of time that aperture allows light to hit the medium, this is called the shutter speed
The shutter is a device that opens and closes in a specific amount of time. Think of it as a door. If you are standing in a room that is full of light and your film or sensor is in another room that is completely dark, then you have to decide how long to open the door between these rooms to properly capture your picture on the sensor or film. If you open the door too long, your picture is overexposed and will be washed out. If you don’t open the door long enough, the exact opposite happens and the photo looks too dark or underexposed.
This is a pretty simple way of laying out how a shutter works. But it gets more complicated when you take aperture into account. Now, to make the analogy complete, think about aperture as the size of the door between the two rooms. If the door is very large, then you may not need to open the door very long to let light in to reach a proper picture. But, on the other hand, if the door is tiny, you may need to open the door for a really long period of time to get the same results.
Most cameras use an automatic calculation to set both aperture and shutter speed. If you have a point and shoot camera or are using a DSLR in Auto mode, then the camera does all the calculations for you. This can be a very good thing if you don’t have the time to think about your camera settings. But there are problems to the camera’s approach that photographers often wish to combat.
In order to take control of shutter speed yourself you usually have to switch to a more manual mode on your camera. On Nikon (the one’s I use) cameras you can switch to S
mode or in a Canon you can switch to Tv
(not sure why its called that but I’m not a Canon user). This mode allows you to set the shutter speed in seconds or fractions of a second and the camera automatically selects the proper aperture to get the right exposure. Of course, if you are really daring or adventurous, you can switch to manual mode (M
for both Nikon and Canon) which allows you to sett both shutter and aperture yourself.
Why Should I Care About Shutter Speed??
For the most part, I don’t concern myself with shutter speed. As we discussed in Photography 101 Lesson 2
Aperture is more important to me because of its effects on Depth of Field
. But, there are times, when I am concerned with shutter speed.
Concern # 1:
I have my aperture set where I want it at f/8 because I want to take a street portrait and I want the person’s face to be sharp but, because its really cloudy, my shutter speed is really long. Because I have to (using our analogy above) open the door to let light in for such a long period of time, I can’t seem to hold the camera steady. With the shutter open for a second or longer my pictures are always blurry because my hand isn’t steady enough to keep the camera in place.
How do I solve this problem?
There are a couple of things you could do. First, you could open your aperture to let more light in. Say, open the aperture to f/5.6 or wider, which will let twice the light in and thus lower your shutter speed by half. Instead of one-second exposure you have one half a second exposure. But this changes your depth of field and could reduce the sharpness of your portrait.
Another option, put your camera on a tripod and tell your subject to hold still. This works well with landscapes that aren’t moving but is tough on people. People, no matter how good they are, tend to move around a lot. This may not be a good solution for a person or an animal.
Final option, turn up your ISO setting (see Photography 101 Lesson 2
for more info on ISO settings). ISO setting effectively reduce your shutter speeds by increasing the sensitivity of your film or sensor. If you think about our room analogy above, ISO might be considered having a little light on in the darkened room where the film or sensor is. With this light on, you don’t need to open your door as long to get a properly exposed picture, but the picture doesn’t come out as clean and clear. It tends to have noise added. Basically, in old film terms, ISO 100 film always came out nice a clear but ISO 1600 film looked horrible. Thanks to digital pictures and new technologies, some cameras can shoot at very high ISOs and still capture great pictures. My old Nikon D80 couldn’t go above ISO 400 before pictures starts to get fuzzy and spotty. My new pro Nikon D700 gives great pictures to ISO 3200. In the case of my D700 I allow the camera to automatically turn up ISO in dark settings because it doesn’t detract from my pictures. If you’re shooting with a point and shoot camera, using ISO to combat shutter speed is a real trade off. A piece of advice: If you MUST have a picture turn up the ISO, but otherwise keep your ISO settings low
What if you want to blur something, like a waterfall? In this case you may actually want to set a high shutter speed in the tens of seconds or even minutes to get an effect. Ever wonder how star streaks are made? It’s done with long shutter speeds on film camera. Sometimes these pictures may be exposed for hours.
An example: You have a waterfall that you want to get a smooth water effect. How do you shoot it? There are a couple of ways to get this effect. The easiest, but not necessarily the greatest, way to get this picture is to switch to Aperture mode and set the smallest aperture you can. On most DSLR lenses this is around f/22 but I have a few lenses that go to f/32 or even lower. Since the “door” is so small, the door must be open longer to achieve a proper exposure. Thus, you stand in front of a waterfall and let the camera open the shutter for seconds. A piece of advice: long shutter speeds are best shot with a tripod. No matter how steady your hand, it will shake some making your picture blurry.
Also, these shots are very hard on bright sunny days. If the light is really bright then it can be almost impossible to open the shutter for long enough to get a blurry waterfall because you risk overexposing the picture. To combat this filters are made specifically to put in front of your lens to make the scene darker
kinda like sunglasses for your camera. We’ll talk more about these some other time.
The best way to get these pictures is to be prepared. Come to a scene knowing you want to capture a slow waterfall or a setting sun. Set your camera up on a tripod, switch to manual mode and set both shutter speed and aperture. Usually high apertures are best (f/22 and above) and low ISO setting (ISO 100 or ISO 50) for getting long, clean, crystal clear exposures. The average person with a camera doesn’t want to fuss with all this thinking. Its great if you’re a bit of a nut like I am, but most people just want to shoot a picture and keep moving!
Just When You Thought You Had It
Nothing in life is ever easy! There is one final point that needs to be discussed in order to understand how aperture and shutter speed fit together in a modern camera. The one thing we never discussed is how the camera judges the light it sees so that it sets the right shutter speed. This is called Metering
because the camera has a built in light meter to judge how light or dark a scene is.
In its most basic setting, the camera looks at the scene through the lens and judges the light in all parts of the scene. There are many names for this type of metering (Nikon calls it Matrix Metering because it is looking at a Matrix of the whole scene
) but ultimately it is the type used by all modern cameras. On a general day you’d want to look at a whole picture, average the amount of light in the whole scene and then choose the right shutter speed to get the proper exposure. This makes complete sense, no?
But there are other types of metering and times when this other metering is useful. For example: My beautiful wife Kelley is making a striking face and I want her perfectly exposed and I don’t care about the background. Since she’s inside and standing in front of a bight window, if I use general metering, the camera will lower the shutter speed so the window isn’t overexposed. The problem with this situation is that, Kelley is now dark while the window is perfectly exposed. Due to all that bright light behind her, the camera chose to lower the shutter speed in order to properly expose the picture on average. But I want Kel properly exposed and don’t care about the window!!!
To correct this, most cameras allow you to change the metering setting. In the case of Nikon (and Canon too I think) cameras they have three settings: Matrix (averaged), Center Weighted, and Spot
. These choices are just like the sound. In Center Weighted metering, the camera increases the weight of the middle 60%!o(MISSING)f the picture when it’s making its average. On the other hand, Spot metering just looks at a 10%!s(MISSING)pot in the middle of the camera to choose shutter speed.
Center weighted (or whatever its called on your camera) is a great option if you care more about the middle of you shot than you do about the edges, but still care about overall exposure. For instance, Mom and Dad are standing in front of a beautiful landscape. They are in shade while the background is really bright. Center weighted will increase the shutter speed to compensate for Mom and Dad being in shade. This will cause them to be brighter but may overexpose the background a bit. Since the metering is still taking the whole scene into account (it increases the priority of the middle but still averages in light from the edges) it increases the shutter speed but not a ton.
Spot is a great option for the above scenario with my wife Kelley. In this case, I put my wife’s face directly in the middle of the picture. Thus the camera only looks at the light in the middle 10%!o(MISSING)f the picture. It sees that she is dark and thus increases the shutter speed to compensate for the darkness of her face. What the camera doesn’t do is take into consideration the fact that the window behind her is really bright. Thus, in the picture, she is perfectly exposed while the background ends up completely overexposed and just looks white.
Once again, I just dumped a ton of info on you. It took me months to really assimilate all the info in these pages so don’t expect it to sink in immediately. My suggestion is play with stuff. Go out with your camera and change settings and shoot. BIG WARNING!!! Always put your setting back to your primary shooting mode when you’re done experimenting. I have ruined a TON of photos by not heeding this advice. If you turn up your ISO setting and then forget to turn it back down, your next photo will be poop and you’ll be sad!
Click on the pictures for better explanations of the shutter speeds and metering